No errors printed

[AndreasBomholtz]

If you give a function to onRefresh with the wrong parameters, there is no error printed, and the callback do not work.

[tacozMacleo]

It should be set up to log out when there is errors with the callbacks that is given. But for some reason, (thread-pool, maybe?) it is not logged.
So I have added a check on the number of parameters the callback can take, so an exception are given before the program starts.
This is added in commit: 9aead67
This should help mitigate those errors until there have been found the reason for the missing logging.